• 한국환경과학회지
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• 제13권1호
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• pp.27-36
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• 2004

Present study analyzed the temporal and spatial characteristics of PM10 pollution in Metropolitan Daegu area based on air pollution monitoring station data and measurements of PM10 concentrations in background area in order to provide essential data for efficient PM10 pollution management. The significant variation of spatial and temporal PM10 concentrations in Daegu area was observed during the study years. The highest maximum PM10 concentration(332 $\mu\textrm{g}$/㎥), average concentration(88 $\mu\textrm{g}$/㎥) and frequency exceeding PM10 daily standard(150 $\mu\textrm{g}$/㎥) were all observed in Namsandong located near a major roadway. The hourly and weekly variations of PM10 concentrations had different pattern for the measurement sites. The monthly and seasonal concentrations exhibited a notable characteristic： the maximum concentration was obtained in spring season, most likely due to Yellow sand effects. Furthermore, this temporal variation of PM10 pollution varied with study site. Meanwhile, the PM10 values measured at the monitoring site, Manchondong, were comparable with those of a control site. The average PM10 concentration ranged from 23 $\mu\textrm{g}$/㎥ to 115 $\mu\textrm{g}$/㎥ with a mean value of 53 $\mu\textrm{g}$/㎥ in the former site and from 22 $\mu\textrm{g}$/㎥ to 91 $\mu\textrm{g}$/㎥ with a mean value of 45 $\mu\textrm{g}$/㎥ in the latter site.

• 한국환경과학회지
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• 제29권7호
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• pp.749-760
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• 2020

This study investigates the characteristics of diurnal, seasonal, and weekly roadside and residential concentrations of PM₁₀ and PM_2.5 in Busan, as well as relationship with meteorological phenomenon. Annual mean PM₁₀ and PM_2.5 concentrations in Busan were 44.2 ㎍/㎥ and 25.3 ㎍/㎥, respectively. The PM_2.5/PM₁₀ concentration ratio was 0.58. Diurnal variations of PM₁₀ and PM_2.5 concentrations in Busan were categorized into three types, depending on the number of peaks and times at which the peaks occurred. Roadside PM₁₀ concentration was highest on Saturday and lowest on Friday. Residential PM₁₀ concentration was highest on Monday and lowest on Friday. Residential PM_2.5 concentration was highest on Monday and Tuesday and lowest on Friday. PM₁₀ and PM_2.5 concentrations were highest on Asian dust and haze, respectively. The results indicate that understanding the spaciotemporal variation of fine particles could provide insights into establishing a strategy to control urban air quality.

• 한국환경보건학회지
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• 제9권1호
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• pp.15-30
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• 1983

The stochastic analysis was carried out to the hourly time series observed at Dae-gu, Wha-Myung and Ku-Mee in order to see water quality variation of the Nack-Dong River during Three months (July, Aug. and Sept.) in each year of 1979 and 1981. As a result of this study, it was found that 1. The simple correlation coefficients between some of the variables were fairly high. For example, the coefficients between Do and WT. were -0.824 (Dae-gu), -0.547 (Wha-myung), and -0.911(Ku-mee). The coefficients between COND and DO. were -0.263(Dae-gu), -0.347(Wha-myung) and -0.881 (Ku-mee). The coefficients between COND and WT. were 0.531 (Dae-gu), 0.361 (Wha-myung) and 0.800 (Ku-mee). 2. Hourly water quality time series of WT and DO existed as dominant 24 hours Periodicity For example, the Aut correlation coefficients about WT were 0.960 (K=1), 0.846(K=24), 0.691(K=48), 0.596(K=72), and 0.453(K=96). The auto-correlation coefficients of Do were 0.968 (K=1), 0.591 (K=24), 0.393 (K=48), 0.349 (K=72) and 0.250 (K=96). 3. Weekly water quality time series of WT and Do varied with the dominant 24 hours periodicity.

• 한국해안·해양공학회논문집
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• 제22권3호
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• pp.171-180
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• 2010

일본 미카와만의 연안 모니터링 부이에서 연속 관측한 수온 및 염분자료를 이용하여 성층의 시간적인 변화 양상을 분석하였다. 분석결과 우선 성층은 뚜렷하고 우세한 1년 주기의 변화 양상을 보이고 있으며, 표층과 저층의 밀도차이로 정의되는 성층강도는 강도가 증가할수록 발생빈도는 기하급수적으로 감소하는 양상을 보이는 것으로 파악되었다. 한편 성층강도의 발생빈도 분포는 정규분포 형태와는 다른 대수 정규분포 또는 지수분포 형태에 보다 근접한 것으로 파악되었다. 수온과 염분의 분산도 분석결과, 저층은 직선 형태의 변화 양상을 보이고 있으나 표층은 곡선 또는 고리(loop) 형태의 변화양상을 보이고 있는 것으로 파악되었다. 한편 성층강도 추정오차를 분석한 결과, 월 4회 관측빈도의 자료를 이용한 오차범위는 본 연구에서와 같이 관측부이의 1일 연속자료를 이용한 오차범위보다 4.45배 이상 증가하는 것으로 파악되었다.

• 대한교통학회지
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• 제19권6호
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• pp.65-73
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• 2001

교통량이 시간의 흐름과 관련이 있는 시계열 데이터라는 개념을 기초로 교통량 패턴을 시계열 분석을 사용하여 분해해 보고자 하였다. 교통량 패턴은 추세치(T)와 계절변동(S), 주기변동(C), 그리고 불규칙변동(I)으로 구분할 수 있었는데 본 연구에서는 불규칙변동을 기상요인을 통해 설명하려는 시도를 하였다. 왜냐하면 교통의 주체인 사람들 행태의 특성상 기상의 변화와 관련이 깊다고 판단을 내렸기 때문이었다. 기상요인으로는 일우량, 일조량, 풍속, 주야율 강설량, 기온 등 여러 가지가 있지만 교통량의 변화와 가장 관련이 깊다고 여겨지는 일우량과 최저기온을 이용하였다. 일단 시계열 성분을 분해하고 나면 이를 이용하여 AADT를 추정하게 되는데, 추정의 결과를 비교하기 위해 AADT 추정방법을 두 가지로 구분하였다. 즉, 기상요인을 사용했을 경우와 그렇지 않을 경우로 나누어 결과를 살펴보았다. 추정 결과를 비교하는 척도로는 RMSE와 U-test를 사용하였다. 결과를 보면 불규칙변동요인을 그대로 사용했을 때보다, 기상요인을 결합한 불규칙변동요인을 사용했을 때 더 추정력이 좋았다. 이것은 각 조사지점의 RMSE와 U-test값을 구한 후 그 지점의 AADT로 나누어 준 결과를 보고 알 수 있었다. 이 연구를 통해 우리는 불규칙변동요인 이용방법의 중요성에 대해 한번 더 생각해 보게 된다. 즉 그것을 설명하는 방법에 의해 기존보다 더 나은 모형을 얻을 수도 있다는 결론에 이르게 된다는 것이다.

• BMB Reports
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• 제30권3호
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• pp.216-221
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• 1997

Changes in pathogenicity of old and successively-cultured isolates of Fusarium oxysporum f. sp. niveum have been observed and the concept that such cultures will become attenuated is generally accepted. However, the genetic basis for this phenomenon has not been studied. In an effort to identify a DNA marker closely linked to variations, DNA methylation was investigated both before and after the successive transfers of F. o. f. sp. niveum isolates on artificial media. A sector of mycelium in F. o. f. sp. niveum race 2 isolate (TXXID) which showed variation in pigmentation and colonial morphology occurred after 18 successive weekly transfers on potato dextrose agar (PDA). The sector characteristics were stable and did not change after more successive transfers. It was shown that DNA methylation preexists in ribosomal RNA gene (rDNA) of F. o. f. sp. niveum and that additional changes in DNA methylation occurred during successive culturing.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 추계학술대회
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• pp.561-565
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• 2006

The paper presents a method of assessing the adequate tapaclty of photovoltaic generation systems for public buildings based on analysis of load variation patterns of customers. When PV systems are installed for supplying power for the customer load, reverse power relay is required by the guideline to be installed at the point of common coupling with the power network. The suggested method analyzes daily, weekly and monthly load demand of the customer that Irishes PV system installation, and determines the appropriate rating of the PV system for preventing PV generation from exceeding the customer demand. This work is expected to support renewable energy dissemination projects of public organizations.

• 상하수도학회지
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• 제26권3호
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• pp.479-486
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• 2012

Runoff characteristics of pollutant loads of the lower Han River was studied before full implementation of Total Pollution Load Management System(TPLMS). Magnitude of macroscopic(annual) fluctuation was in the order of Namhan River > Han River > Bukhan River, gross weight TP > gross weight TN > gross weight BOD, gross weight deviation > concentration deviation. Flux variation was higher than that of concentration. Microscopic(weekly) fluctuation showed similar pattern to macroscopic scale. TP showed the highest deviation resulting in the lowest reliability. 60% of annual flux passed during summer 3months resulting in 43-46% pass of gross weight at the lower Han River. Strong correlation was found between flux and gross weight especially in gross weight TN. Gross weight pollution increased as high as 400% while passing Seoul area due to the concentration. The deviation from moving average increased during summer season in the gross weight TP and BOD. Seasonal tendency was confirmed especially in gross weight TN and TP using autocorrelation function.

• 한국건설관리학회논문집
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• 제6권1호
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• pp.49-57
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• 2005

Construction labor productivity, which is the greatest source of variation in overall construction productivity, is the critical factor for determining the project performance in terms of time and cost, especially during scheduled overtime when extra time and cost are invested. The objective of this research is to select an appropriate type of probability distribution function representing the variability of daily labor productivity during overtime. Based on the results of statistical data analysis of labor performance during different weekly work hours, lognormal distribution is selected in order to take advantage of easiness of generating correlated random numbers. The selected lognormal distribution can be used for development of a simulation model in construction scheduling, cost analysis, and other applications areas where representation of the correlations between variables are essential.

• 한국태양에너지학회 논문집
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• 제29권4호
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• pp.48-57
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• 2009

Energy demands for hotels in Korea are surveyed and statistically analyzed to develop calculation models for a simulation. Daily energy loads of 16 hotels located in Seoul, Busan, Daegu, Inchon, and Daejon are analyzed based on energy log sheets. Detailed hourly loads are field measured for 3 hotels that are carefully selected among the surveyed. One of the salient features for energy consumption by hotels is their weekly periodicity. Relatively large values of deviations are observed for both heat and electricity loads through the country. The mains factors are: location, hotel grade (luxuriousness) and insulation. Detailed quantitative information such are annual average, daily variation, and hourly patterns are provided.